EPE Association: EPE 2016 - DS1i: Batteries, Battery Chargers and Management Systems

EPE 2016 - DS1i: Batteries, Battery Chargers and Management Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 08: e-Mobility > EPE 2016 - DS1i: Batteries, Battery Chargers and Management Systems

   [return to parent folder]

   A Modular Multilevel Topology Using Power Electronic Transformers for the Modular Drivetrains of Electric Vehicles
By Fengqi CHANG [View]
[Download]

Abstract: This paper proposed a modular multilevel topology using power electronics transformersfor the modular drivetrain of electric vehicles (EV). Because of its high modularity, the topology canbe easily applied to a wide range of EVs, from personal vehicles to passenger cars. Compared withtwo conventional modular multilevel converters, fewer submodules are needed and its control is thussimpler. The topology can also balance voltage of batteries without an equalization circuit and has lowharmonics distortion. Moreover, according to the simulation results, the topology has higher overallefficiency than the conventional 6-switch 2-level inverter structure in synthesized driving cycles.

   Design Approach and Interoperability Analysis of Wireless Power Transfer Systems for Vehicular Applications
By Mohamed EL BAGHDADI [View]
[Download]

Abstract: This article gives an overview of the analysis and modeling for high power wireless power transfer for electric vehicles. The main system under investigation is the series-parallel-series topology. A simulation study, optimized design and finite elements results are presented. The study focusses on the design of the optimized systems for diverse power outputs, and investigates their interoperability.

   Design Optimization of Various Contactless Power Transformer Topologies for Wireless Charging of Electric Vehicles
By Hedieh MOVAGHARNEJAD [View]
[Download]

Abstract: Contactless power transfer (CPT) has demonstrated its ability as a safe, efficient and convenient way for electric vehicle (EV) charging systems by providing acceptable power levels with tolerance to misalignments. The magnetic design of the primary and secondary coupler is one of the most critical parts of a CPT system design. This paper investigates various configurations of loosely coupled magnetic couplers, which could possibly be used in CPT systems to provide wireless charging of the on- board battery of EVs. Six different structures were investigated in this paper and important factors influencing the power transfer at a fixed frequency with excitation of the primary pad were considered as design metrics. Detailed comparisons of each topology with its structure characteristics are extracted. All the models presented in this paper are simulated with a 3D finite element modeling software package MAXWELL. Each configuration is designed so that which is able to provide at least 250 VA of power transfer both at the air gap and lateral misalignment of 20 cm. A system consisting of a double D coil in the primary side and a double D coil with an overlap in the secondary side (DD- DD\_int) seen to have the highest k and resonant power per quality factor (P Resonant /Q) when the couplers are placed precisely aligned and also have better coupling even at high misalignment positions in comparison with other topologies investigated in this paper. A DD-DD\_int configuration of couplers has been built to validate the simulation results. The couplers were series tuned and provided an output power of 2 kW with an efficiency of 94\% when the couplers are centered.

   Development of a Battery Energy Loss Observer Based on Improved Equivalent Circuit Modelling
By AHMED FARES [View]
[Download]

Abstract: This paper proposes a new energy loss observer for batteries that has a good accuracy and low complexity. This observer can provide a support for battery management systems (BMS) in terms of predicting battery energy losses and/or battery internal temperature for a given load profile, and this enhances BMS capabilities for predictive and corrective actions. The typical observer requires an accurate battery model that represents accurately the internal resistance of the battery, and therefore battery modelling guidelines to produce a simplified equivalent circuit model (ECM) have been proposed. Experiments to validate the accuracy of the proposed model have been performed on a LiFePO4 (3.6V/8Ah) battery cell. The model parameter estimation has been achieved by fitting the model impedance to data obtained from battery electrochemical impedance spectroscopy. The energy loss estimation based on the proposed observer showed good accuracy with maximum error of ±2\% under different load profiles operated within the targeted frequency range.

   Electrical Failure Mode and Effect Analysis of a 3.3 kW Onboard Vehicle Battery Charger
By Saeid HAGHBIN [View]
[Download]

Abstract: Reliability is one important aspect for further improvement of power electronic converters. The improvement trend is towards a higher power density, and a higher efficiency with a lower price. Those performance indices are normally in contradiction with the reliability. A failure mode and effect analysis (FMEA) of a 3.3 kW onboard battery charger is presented for the electrical part of the charger. The FMEA results are used to prioritize, investigate and analyze important fault cases in semiconductors, dc bus capacitors and sensors. Possible reasons of each fault, appropriate fault detection methods, possible mitigation algorithms and some design improvements are shortly presented. The calculated risk numbers confirm that the reliability of the charger is considerable improved consequently.

   High Frequency Magnetic Resonant Coupling Wireless Power Transfer System for Middle Power Charging Applications
By Jeihoon BAEK [View]
[Download]

Abstract: This paper presents the design and implementation of a high frequency magnetic resonant coupling wireless power transfer (WPT) for middle power charging applications. The size and efficiency of resonator are depending on the resonant coupling frequency in the WPT system with magnetic resonant coupling. To improve the WPT efficiency, power capacity and resonator size, a high resonant coupling frequency is commonly desirable. However, the silicon based high frequency switching devices for middle power converter are limited. Also, power amplifier converter at high frequency has low efficiency. Therefore, this paper proposes a high frequency full-bridge inverter using Gallium Nitride (GaN) transistors for less than hundred watt charging applications. In order to verify the proposed system efficiency, simulation and experiments has been carried out.

   High performance drives for hybrid electric vehicles through voltage stabilization
By Quentin WERNER [View]
[Download]

Abstract: This paper deals with the approach of integrating a bidirectional boost-converter into the drivetrain of a (hybrid) electric vehicle in order to exploit the full potential of the electric drives and the battery. Currently, the automotive norms and standards are defined based on the characteristics of the voltage source. The current technologies of batteries for automotive applications have voltage which depends on the load and the state-of charge. The aim of this paper is to provide better system performance by stabilizing the voltage without the need of redesigning any of the current components in the system. To show the added-value of the proposed electrical topology, loss estimation is developed and proved based on actual components measurements and design. The component and its modelling is then implemented in a global system simulation environment of the electric architecture to show how it contributes enhancing the performance of the system.

   Hybrid Lead-Acid/Lithium-Ion Energy Storage System with Power-Mix Control for Light Electric Vehicles
By Steven CHUNG [View]
[Download]

Abstract: The performance versus cost tradeoffs of a fully electric, hybrid energy storage system (HESS), usinglithium-ion (LI) and lead-acid (PbA) batteries, are explored in this work for a light electric vehicle (LEV).While LI batteries typically have higher energy density, lower internal resistance and longer lifetimethan PbA batteries, the module cost of LI batteries are typically three to five times the cost of PbAbatteries. The objective is to design a HESS configuration that 1) is cost-competitive with a PbA singleenergy storage system (SESS) and 2) maintains most of the performance benefits of a lithium SESS.A modular HESS architecture with a bi-directional dc-dc converter and controller is proposed, and apower-mix algorithm with active inter-chemistry battery state-of-charge (SOC) balancing is presented,simulated, and verified experimentally. The batteries, converter and control algorithm are modeled inMATLAB, and the effects of total ESS energy, vehicle loading, DOD, and speed are explored. The costand performance of the HESS are assessed side-by-side with PbA and LI single energy storage system(SESS) configurations of comparable total energy, using expected vehicle range as the performancemetric. The experimental HESS has a total projected cost midway between the SESS PbA cost and theSESS Li cost, while providing 17\% range and 22.5\% efficiency increase over the SESS PbA vehicle.

   Investigation of the Zero-Current Switched Class E Converters for automotive Wireless Power Transfer Inductive Charging Applications
By Sebastian SALICH [View]
[Download]

Abstract: The zero-current switched class E converters are investigated for automotive wireless power transferinductive charging applications. In comparison to the class D converters, typically used for thisapplication, the class E converters have only one active switch on the primary-side of the inductiveenergy transfer coils and the resonant tank current magnitude is independent from the magnitude ofthe current in this active switch. The paper presents full details of the Class E2 converter analysesincluding converters with series and parallel resonant circuits and compares the two topologies. A fullsizeprototype converter has been built and tested to confirm theoretical predictions. The converterperformance is investigated, when operated with the required variation of the magnetic coupling,battery-voltage and output power level determined by the automotive charging application.

EPE 2016 - DS1i: Batteries, Battery Chargers and Management Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 08: e-Mobility > EPE 2016 - DS1i: Batteries, Battery Chargers and Management Systems
	[return to parent folder]

	A Modular Multilevel Topology Using Power Electronic Transformers for the Modular Drivetrains of Electric Vehicles By Fengqi CHANG	[View] [Download]
Abstract: This paper proposed a modular multilevel topology using power electronics transformersfor the modular drivetrain of electric vehicles (EV). Because of its high modularity, the topology canbe easily applied to a wide range of EVs, from personal vehicles to passenger cars. Compared withtwo conventional modular multilevel converters, fewer submodules are needed and its control is thussimpler. The topology can also balance voltage of batteries without an equalization circuit and has lowharmonics distortion. Moreover, according to the simulation results, the topology has higher overallefficiency than the conventional 6-switch 2-level inverter structure in synthesized driving cycles.

	Design Approach and Interoperability Analysis of Wireless Power Transfer Systems for Vehicular Applications By Mohamed EL BAGHDADI	[View] [Download]
Abstract: This article gives an overview of the analysis and modeling for high power wireless power transfer for electric vehicles. The main system under investigation is the series-parallel-series topology. A simulation study, optimized design and finite elements results are presented. The study focusses on the design of the optimized systems for diverse power outputs, and investigates their interoperability.

	Design Optimization of Various Contactless Power Transformer Topologies for Wireless Charging of Electric Vehicles By Hedieh MOVAGHARNEJAD	[View] [Download]
Abstract: Contactless power transfer (CPT) has demonstrated its ability as a safe, efficient and convenient way for electric vehicle (EV) charging systems by providing acceptable power levels with tolerance to misalignments. The magnetic design of the primary and secondary coupler is one of the most critical parts of a CPT system design. This paper investigates various configurations of loosely coupled magnetic couplers, which could possibly be used in CPT systems to provide wireless charging of the on- board battery of EVs. Six different structures were investigated in this paper and important factors influencing the power transfer at a fixed frequency with excitation of the primary pad were considered as design metrics. Detailed comparisons of each topology with its structure characteristics are extracted. All the models presented in this paper are simulated with a 3D finite element modeling software package MAXWELL. Each configuration is designed so that which is able to provide at least 250 VA of power transfer both at the air gap and lateral misalignment of 20 cm. A system consisting of a double D coil in the primary side and a double D coil with an overlap in the secondary side (DD- DD\_int) seen to have the highest k and resonant power per quality factor (P Resonant /Q) when the couplers are placed precisely aligned and also have better coupling even at high misalignment positions in comparison with other topologies investigated in this paper. A DD-DD\_int configuration of couplers has been built to validate the simulation results. The couplers were series tuned and provided an output power of 2 kW with an efficiency of 94\% when the couplers are centered.

	Development of a Battery Energy Loss Observer Based on Improved Equivalent Circuit Modelling By AHMED FARES	[View] [Download]
Abstract: This paper proposes a new energy loss observer for batteries that has a good accuracy and low complexity. This observer can provide a support for battery management systems (BMS) in terms of predicting battery energy losses and/or battery internal temperature for a given load profile, and this enhances BMS capabilities for predictive and corrective actions. The typical observer requires an accurate battery model that represents accurately the internal resistance of the battery, and therefore battery modelling guidelines to produce a simplified equivalent circuit model (ECM) have been proposed. Experiments to validate the accuracy of the proposed model have been performed on a LiFePO4 (3.6V/8Ah) battery cell. The model parameter estimation has been achieved by fitting the model impedance to data obtained from battery electrochemical impedance spectroscopy. The energy loss estimation based on the proposed observer showed good accuracy with maximum error of ±2\% under different load profiles operated within the targeted frequency range.

	Electrical Failure Mode and Effect Analysis of a 3.3 kW Onboard Vehicle Battery Charger By Saeid HAGHBIN	[View] [Download]
Abstract: Reliability is one important aspect for further improvement of power electronic converters. The improvement trend is towards a higher power density, and a higher efficiency with a lower price. Those performance indices are normally in contradiction with the reliability. A failure mode and effect analysis (FMEA) of a 3.3 kW onboard battery charger is presented for the electrical part of the charger. The FMEA results are used to prioritize, investigate and analyze important fault cases in semiconductors, dc bus capacitors and sensors. Possible reasons of each fault, appropriate fault detection methods, possible mitigation algorithms and some design improvements are shortly presented. The calculated risk numbers confirm that the reliability of the charger is considerable improved consequently.

	High Frequency Magnetic Resonant Coupling Wireless Power Transfer System for Middle Power Charging Applications By Jeihoon BAEK	[View] [Download]
Abstract: This paper presents the design and implementation of a high frequency magnetic resonant coupling wireless power transfer (WPT) for middle power charging applications. The size and efficiency of resonator are depending on the resonant coupling frequency in the WPT system with magnetic resonant coupling. To improve the WPT efficiency, power capacity and resonator size, a high resonant coupling frequency is commonly desirable. However, the silicon based high frequency switching devices for middle power converter are limited. Also, power amplifier converter at high frequency has low efficiency. Therefore, this paper proposes a high frequency full-bridge inverter using Gallium Nitride (GaN) transistors for less than hundred watt charging applications. In order to verify the proposed system efficiency, simulation and experiments has been carried out.

	High performance drives for hybrid electric vehicles through voltage stabilization By Quentin WERNER	[View] [Download]
Abstract: This paper deals with the approach of integrating a bidirectional boost-converter into the drivetrain of a (hybrid) electric vehicle in order to exploit the full potential of the electric drives and the battery. Currently, the automotive norms and standards are defined based on the characteristics of the voltage source. The current technologies of batteries for automotive applications have voltage which depends on the load and the state-of charge. The aim of this paper is to provide better system performance by stabilizing the voltage without the need of redesigning any of the current components in the system. To show the added-value of the proposed electrical topology, loss estimation is developed and proved based on actual components measurements and design. The component and its modelling is then implemented in a global system simulation environment of the electric architecture to show how it contributes enhancing the performance of the system.

	Hybrid Lead-Acid/Lithium-Ion Energy Storage System with Power-Mix Control for Light Electric Vehicles By Steven CHUNG	[View] [Download]
Abstract: The performance versus cost tradeoffs of a fully electric, hybrid energy storage system (HESS), usinglithium-ion (LI) and lead-acid (PbA) batteries, are explored in this work for a light electric vehicle (LEV).While LI batteries typically have higher energy density, lower internal resistance and longer lifetimethan PbA batteries, the module cost of LI batteries are typically three to five times the cost of PbAbatteries. The objective is to design a HESS configuration that 1) is cost-competitive with a PbA singleenergy storage system (SESS) and 2) maintains most of the performance benefits of a lithium SESS.A modular HESS architecture with a bi-directional dc-dc converter and controller is proposed, and apower-mix algorithm with active inter-chemistry battery state-of-charge (SOC) balancing is presented,simulated, and verified experimentally. The batteries, converter and control algorithm are modeled inMATLAB, and the effects of total ESS energy, vehicle loading, DOD, and speed are explored. The costand performance of the HESS are assessed side-by-side with PbA and LI single energy storage system(SESS) configurations of comparable total energy, using expected vehicle range as the performancemetric. The experimental HESS has a total projected cost midway between the SESS PbA cost and theSESS Li cost, while providing 17\% range and 22.5\% efficiency increase over the SESS PbA vehicle.

	Investigation of the Zero-Current Switched Class E Converters for automotive Wireless Power Transfer Inductive Charging Applications By Sebastian SALICH	[View] [Download]
Abstract: The zero-current switched class E converters are investigated for automotive wireless power transferinductive charging applications. In comparison to the class D converters, typically used for thisapplication, the class E converters have only one active switch on the primary-side of the inductiveenergy transfer coils and the resonant tank current magnitude is independent from the magnitude ofthe current in this active switch. The paper presents full details of the Class E2 converter analysesincluding converters with series and parallel resonant circuits and compares the two topologies. A fullsizeprototype converter has been built and tested to confirm theoretical predictions. The converterperformance is investigated, when operated with the required variation of the magnetic coupling,battery-voltage and output power level determined by the automotive charging application.